Talk:Potamon fluviatile

Potamon fluviatile has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.

Article milestones
Date	Process	Result
March 18, 2010	Good article nominee	Listed

A fact from this article appeared on Wikipedia's Main Page in the "Did you know?" column on December 17, 2009.

The text of the entry was: Did you know ... that crabs of the species Potamon fluviatile may have lived in Rome since before the Romans?

GA Review

This review is transcluded from Talk:Potamon fluviatile/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Ucucha 01:15, 15 March 2010 (UTC)[reply]

~~The lead seems rather short, should probably be at least two paragraphs.~~

I've expanded the lead a little, but I have struggled to find much to say without repeating text from later verbatim. Please let me know if it needs more. --Stemonitis (talk) 07:40, 16 March 2010 (UTC)[reply]

Length is good now. I noticed that the fact that the Roman population is the only one in the middle of a large city is not in the body of the article. Ucucha 13:14, 16 March 2010 (UTC)[reply]

Done --Stemonitis (talk) 17:59, 17 March 2010 (UTC)[reply]

~~Technical term that needs inline explanation: pleopod~~

Done --Stemonitis (talk) 07:40, 16 March 2010 (UTC)[reply]

~~You first say it only occurs south of the watershed in the Tusco-Emilian Apennines, and then that it occurs north to the Po. Aren't the Tusco-Emilian Apennines directly south of the Po?~~

They are, but so are other parts of the Apennines. I don't really know the distribution that well (and I'm not sure anyone has published a detailed map for Italy), but it could be explained by a presence on the north side of the Ligurian Apennines, but not on the north side of the Tusco-Emilian Apennines specifically. It certainly occurs north-east of the more southerly parts of the Apennines. I have tried to limit myself to reported what the references say, rather than trying to add my own interpretation, so it may just be that the sources conflict slightly. The species' range has evidently changed in northern Italy over the last 150 years, which might go some way to explaining that. --Stemonitis (talk) 07:40, 16 March 2010 (UTC)[reply]

OK, fair enough.

~~The taxonomy section is a little thin. Perhaps add something about other recognized subspecies and its original description.~~

I've added in Pretzmann's "nationes", and the other former subspecies. I'm worried that this might be giving undue weight to taxa that have been utterly ignored, as far as I can see. I've also added in some information about the wider genus. I can't seem to find a copy of Herbst (1785) to expand on the original description. --Stemonitis (talk) 07:40, 16 March 2010 (UTC)[reply]

This is apparently a reprint of it, with good presumably PD images. I can't find the actual book either; I think the taxonomy section is good now.

The distribution map doesn't seem to agree with the text.

I noticed that when I was writing the article, but I didn't like to change it until I was sure. I have seen no evidence that the species occurs on Corsica or Sardinia, or that the Croatian populations are separated geographically from the Greek ones. Accordingly, I've made a new map, correcting those errors. I'm less certain about the Italian distribution, though (see above). --Stemonitis (talk) 07:40, 16 March 2010 (UTC)[reply]

There are still some small discrepancies: the body of the article doesn't mention that it occurs in Kosovo and Bosnia. Ucucha 13:14, 16 March 2010 (UTC)[reply]

I am struggling a little here. I can't find any source that explicitly states that P. fluviatile either does or does not occur in Bosnia or Kosovo. As such, I am unsure whether to add Bosnia to the text, or remove it from the map. The smallest-scale study I've been able to find for that area (Jesse et al., 2009) also doesn't mention Bosnia, but does refer to Dalmatia, when it could have said Croatia. I'm probably reading too much into this, but that could be an attempt to cover parts of Bosnia (albeit only a tiny part – nothing like the area I drew on the map). Parts of the former Yugoslavia have been underexplored by biologists over the last few decades, for obvious reasons, and it seems quite likely to me that nobody's really checked to see how widespread the different Potamon species are in places like Bosnia-Herzegovina. On the other hand, the IUCN Red List gives an explicit list of countries, with the clear implication that it doesn't occur in any countries that are not listed there. Bosnia is not included, but then again, a distribution encompassing Croatia, Albania and Montenegro but not Bosnia seems unlikely. Either approach seems like WP:OR. Even stating (either in words, or through some kind of symbol on the map) that the distribution in Bosnia is uncertain would be OR: no-one else seems to have said so. I'm happy to redraw the map or rephrase the text in any way; I'm just not sure what the best approach would be. Any suggestions? --Stemonitis (talk) 17:59, 17 March 2010 (UTC)[reply]

I see the problem. I think it would be best to reduce the range in the interior of the Balkans so as to remove the piece in Kosovo and make the piece in Bosnia smaller. I think you can reasonably interpret "Dalmatia" to include parts of Bosnia (as our article says).

Two more things: Jesse et al. (p. 2211) state that the Peloponnesos population is a separate, cryptic species, and the Red List says that a recent taxonomic review (Brandis et al. 2000) doesn't recognize P. f. lanfrancoi. Shouldn't that be in the article? Ucucha 18:17, 17 March 2010 (UTC)[reply]

Done. --Stemonitis (talk) 07:26, 18 March 2010 (UTC)[reply]

Thanks. I am now passing this as a GA. Ucucha 12:39, 18 March 2010 (UTC)[reply]

Otherwise, it looks good; sources appear reliable and images are free. Ucucha 01:15, 15 March 2010 (UTC)[reply]

refs for freshwater crabs in other major cities

Hi, these are a few references for freshwater crabs in major cities: Cairo: http://www.landesmuseum.at/pdf_frei_remote/ANNA_99B_0571-0589.pdf Johannesburg (Germiston): http://www.sciencedirect.com/science/article/pii/S0147651398916992 Depending on whether or not one considers Eriocheir sinensis 'freshwater', London, Hamburg, etc.: http://www.europe-aliens.org/pdf/Eriocheir_sinensis.pdf (and many others). I found the statement in National Geographic highly bizarre, could it be that they only meant Potamon fluviatile? I have never seen this species so I don't know how common it is. The two Potamonautes spp. are extremely common at the two locations. Rainbowwrasse (talk) 10:13, 23 August 2011 (UTC)[reply]

Without necessarily defending the statement reproduced in the article, I can imagine how the authors might justify it. The presence of crabs in the Nile at Cairo isn't quite the same as having them close up among the human population, as they are in Rome. The Thames in London is entirely tidal, as is the Elbe in Hamburg, so they could easily be discounted from "freshwater" if one was using a strict definition. I'm not even sure that Cumberlidge (1997) [the first link above] claims that Potamonautes niloticus is present in the city of Cairo – might the text "Cairo" and "Assuan" not refer to Cairo Governorate and Aswan Governorate? In any case, we have a satisfactorily cited claim that Potamon fluviatile is the only freshwater crab in the centre of a large city, and no reference that explicitly says it isn't. Any interpretation that we make based on other sources could be seen as original research. --Stemonitis (talk) 10:17, 23 August 2011 (UTC)[reply]

I probably would not count mitten crabs either, but there is no reason to believe that 'Cairo' was meant as 'Cairo Governorate'. The governorates are referred to as such, whereas the city is just called 'Cairo' (and is far more urbanized than Rome). We might more easily assume that 'freshwater crabs' in the NG piece only refers to Potamon fluviatile. One of the sources also lists further major cities such as Yaounde and Nairobi as localities. The problem with the claim is that it is simply so bizarre that it's difficult to find a source that explicitly says it isn't true; it's similarly difficult finding a source stating that pigs cannot fly. Freshwater crabs are so widespread in the waterways of (at least African, can't speak for others) cities that the best one can hope for is a passing mention that someone collected them there; it's very unlikely that someone would explicitly state 'freshwater crabs are common in X'. I do not see how interpreting (if on can call it that) the fact that someone found crabs in, say, Cairo or Yaounde as an indication that they must therefore occur in those cities is original research. Also, I am not saying that the article should say that freshwater crabs are commonly found in cities, I am just saying that the the statement that out of all the cities in the world, only Rome has freshwater crabs should be left out (or possibly change 'freshwater crabs' to P fluviatile). I know that prima facie this looks like the 'verifiability, not truth' criterion, but this is a relatively minor point and so obviously false that I think it would be better to just leave it out. Also, P. fluviatile is known as the freshwater crab in Italian (Il granchio d’acqua dolce), so it is quite likely that only this species was originally meant. I therefore think that the NG source is not necessarily all that precise. That is my opinion, but in a way it's your article, so I am not going to challenge it (great job on all the invertebrate articles, BTW, you seem to be responsible for a lot of them!). Rainbowwrasse (talk) 18:04, 23 August 2011 (UTC)[reply]

I can't believe they would mean just P. fluviatile and state "freshwater crabs". They must just be wrong. I think I do now agree that it's best to simply take it out; I'll do that now. --Stemonitis (talk) 18:41, 23 August 2011 (UTC)[reply]